Atomic Theory

Multiple Choice

Who was the first to suggest the existence of fundamental particles called atoms?

• Democritus

• Dalton

• Bohr

• Rutherford

Fill in the Blanks

Dalton’s theory states that all elements are composed of indivisible atoms, which he described as a solid or hard

.

Multiple Choice

Which scientist is credited with formulating the first atomic theory based on the study of chemical reaction ratios?

• John Dalton

• JJ Thomson

• Ernest Rutherford

• Niels Bohr

Multiple Select

According to Dalton’s Atomic Theory, which of the following statements are correct?

• All matter is composed of atoms.

• Atoms of different elements have identical properties.

• Atoms can combine in simple whole-number ratios to form compounds.

• Atoms of a given element are identical in mass and properties.

Multiple Choice

What major discovery did JJ Thomson make using the cathode ray tube experiment?

• The existence of protons

• The existence of electrons

• The atomic nucleus

• The neutron

Multiple Choice

Which atomic model proposed that electrons and positive charges were dispersed throughout the atom like 'plums in a pudding'?

• Dalton’s Model

• Rutherford’s Model

• Bohr’s Model

• Thomson’s Model

Open Ended

Explain how Rutherford’s gold foil experiment led to a new understanding of atomic structure.

Multiple Choice

According to Bohr's atomic model, where are electrons found in an atom?

• In specific energy levels orbiting the nucleus

• Randomly scattered throughout the atom

• Only in the nucleus

• In fixed positions outside the atom

Open Ended

Explain what happens to an electron when it absorbs energy according to Bohr's model.

Fill in the Blanks

When an electron returns to its ground state, it releases energy in the form of a

.

Multiple Choice

What is the maximum number of electrons that can be held in the third principal energy level (n=3)?

• 2

• 8

• 18

• 32

Multiple Select

Which of the following statements about Principle Energy Levels (PELs) are correct?

• Each PEL can hold a specific maximum number of electrons.

• Electrons in higher PELs have more energy.

• All PELs can hold the same number of electrons.

• The formula 2n^2 determines the maximum electrons in a PEL.

Multiple Choice

How did Schrodinger's model of the atom differ from Bohr's model?

• Electrons move in fixed orbits in Schrodinger's model.

• Electrons are found in regions called orbitals in Schrodinger's model.

• Schrodinger's model places electrons only in the nucleus.

• Schrodinger's model does not include a nucleus.

Multiple Choice

Which subatomic particle is found in the nucleus and has no electrical charge?

• Proton

• Neutron

• Electron

• Positron

Fill in the Blanks

The total charge of an atom is always

when the number of protons equals the number of electrons.

Multiple Select

Which of the following statements about protons are correct?

• They are positively charged.

• They are found in the nucleus.

• They have a mass of 1 amu.

• They are the lightest subatomic particle.

Fill in the Blanks

The sum of the number of protons and neutrons in an atom is called the

number.

Multiple Choice

What is the significance of valence electrons in an atom?

• They determine the atom's mass.

• They are responsible for chemical bonding.

• They are found in the nucleus.

• They have no effect on the atom's properties.

Multiple Choice

Based on the table of hydrogen isotopes, which isotope has the greatest number of neutrons?

• H-1 (Protium)

• H-2 (Deuterium)

• H-3 (Tritium)

• All have the same number of neutrons

Multiple Choice

Which of the following statements best describes isotopes?

• Atoms of the same element with different numbers of neutrons and different mass.

• Atoms of different elements with the same number of protons.

• Atoms of the same element with the same number of neutrons.

• Atoms of different elements with different numbers of electrons.

Fill in the Blanks

Fill in the blank: The number of neutrons in an atom is calculated by subtracting the atomic number from the

number.

Open Ended

Explain how to determine the number of neutrons in an atom if you know its atomic number and mass number. Use examples from the slides to support your answer.

Multiple Choice

Which factors are used to calculate the atomic mass of an element as found on the periodic table?

• The average of the isotopes' mass numbers and their abundance

• The number of protons and electrons

• The mass of the most common isotope only

• The sum of atomic numbers of all isotopes

Open Ended

Describe the steps involved in calculating the atomic mass of an element when given the percent abundance and mass numbers of its isotopes.

Multiple Choice

Which of the following statements best summarizes Democritus' view of atoms?

• Atoms are indivisible and indestructible particles.

• Atoms are made up of smaller particles.

• Atoms can be created and destroyed easily.

• Atoms are visible to the naked eye.

Open Ended

How did Democritus contribute to the development of atomic theory?